Collected my new Mesa MK4 rev b combo tonight.
€1150 in flight case.
Got to the studio and plugged it in and am extremely happy.
Ran it into my mesa recto cab and dialed in a killer sound in about half an hour.
I have heard these are hard to dial but it took no time at all to get an amazing sound.
Initial impression is that it smokes my triple recto.
Really full aggressive mid range without the recto fizz.
It is REALLY loud. Master at 2 is deafening through recto cab.
Fan is also really loud. Does anyone know what to do about the fan noise?
Is the fan needed at all. It's an open back combo.
What are the options for replacing the fan with a quitter one?
Re-amp of Lasse/Mago DIs

LOVE this amp so much! And I also own a 6505+. Different beasts entirely, but nothing beats the Mark IV for me!
As for fan noise.. It's never been an issue for me really. I know it's loud but meh :P Just disconnect it if you must. It shouldn't be an issue ^_^

When electronic components get too hot, their life-span will get shorter and shorter.
So it is best not to remove the fan (especially in the summer) - if the original configuration has it, it means that the designer thought that it was absolutely necessary.

Your options are to install a bigger diameter, slower rpm fan, or use an air duct tube to move the fan as far away from the microphone as you want (even to another room).

You made the right choice. My optimal settings for the lead channel were: 8, 8, 2, 5, 8 and EQ flat but 750hz knob rolled down until it sounds "right" with the cabinet. Umm... I actually have a small favor to ask... I'll PM you.

This amp slays the more I get used to it.
I have disconnected the fan so hopefully it won't overheat.
It sounded like a jumbo jet taking off :-)
I will order a new fan from Mesa tomorrow.
I recorded a Lamb of God style band last year and really struggled to get the right sound.
I re-amped it today with Will Adler's settings found on the web and it sounds fantastic.
No boost, no multiband.

Grats on the new amp,i love mine, it's my go to for anything heavy. Speaking of the fan, mine has never worked since i got it, should i have it checked? It came unplugged and i tried plugging it a few times and it just never spins.

Just a tad of low cut on the guitars. Other than that it's a raw tone.

Not bad man I like. Can I ask though, as you've HAD a Mk IV before, or you love it etc. Do you find the AXE almost lifeless in comparison? I mean, just listening to that clip and then that actual MK IV clip, in my opinion, though the tonal quality is there, it almost sounds dead in comparison. Surely I'm not imagining it...

I've been struggling to get my Mark IV tone and feel out of the Axe-Fx and I'm pretty sure it's mainly because there's no graphic EQ in the amp model. Also I'd say that the Axe-Fx Mark IV is more scratchy than the real thing.

In the end real amps will always win we all know that. If I could afford all these amps I'd own them but that's not the case. The analog additions are simply missing like amp hums and feedback etc.

Anyways you can't really compare these clips since my settings were different. I can post an A/B test of the match EQ'd process so we'll see if there's a difference!

Okay so the first time around it's my Axe-Fx with match EQ and the same amp settings. The Axe clip is a tad louder but not much. Anyways... you can hear some analog things missing but I'd say it's pretty ridiculously close.

Ahhh schweet! Cheers for doing that. My aim wasn't to be Digital VS Analogue etc.. I think we both know that there are obvious differences. But I meant more so, even though you've set it up with the AXE etc. Response wise etc, does it FEEL like playing through the amp or does it feel stiff etc? I haven't played around with the AXE enough. But I have a mate who swears by the Mark IV mode on it ^_^

It's actually really hard to tell since I can't straight up A/B the two. I must say that the Axe-Fx really does feel like a real tube amp so the hype is/was real but ofcourse I can't guarantee that the feel is just like a Mark IV. Even on a Mark IV there are differences. I had EL34s in the outer sockets on that amp and to me that made a world of difference and placed the amp somewhere between British and American high gain. There is no amp sim for that at least.

Some guys have argued that the Axe-Fx Mark IV isn't as tight as the real power amp / 2:90 Mesa power amp and have used the Axe-Fx FX blocks to compensate for that. So I'm sure it's not exactly the same but personally I feel like in this situation it's good to look at the big picture. This one box with a midi pedal on a gig and I'm sure no one in the audience can tell a difference. Quick portable rig with as many amps as I could ever want for 1500€. A Mark IV on a stage with a Recto cab is far from portable, affordable and versatile on the fly.

To conclude there might be a difference but it's so small that I wouldn't worry. A mic misplaced by half an inch will sound more different that an Axe-Fx rig.

That sounds fantastic.
Glad I could play a part in you getting such a great tone from the axe.
I would love to hear the same riff re-amped through the axe's stock MKIV model to hear the difference your match process made.

How does the axefx react to lower signals or low gain like the intro to Deftones "you've seen the butcher" for example. The way the signal rings after the mutes on that song. Sounds fantastic and I think would be hard to emulate.

I have pretty much all the amps I need for now so don't need an axefx.
I have triple recto, 6505, dsl100, marshall 8100, triamp mk2 and now the mesa MK4. May get a Vox next. The clean on the MK4 sounds very like a fender deluxe so don't need a fender now. I also have recto cab, marshall v30 cab and orange cab. We should get together and make some axe-fx patches for my amps and cabs and paypal them

How does the axefx react to lower signals or low gain like the intro to Deftones "you've seen the butcher" for example. The way the signal rings after the mutes on that song. Sounds fantastic and I think would be hard to emulate.

I have pretty much all the amps I need for now so don't need an axefx.
I have triple recto, 6505, dsl100, marshall 8100, triamp mk2 and now the mesa MK4. May get a Vox next. The clean on the MK4 sounds very like a fender deluxe so don't need a fender now. I also have recto cab, marshall v30 cab and orange cab. We should get together and make some axe-fx patches for my amps and cabs and paypal them

Mick I need the Triamp tone! Just kidding man you've done enough.

The Axe-Fx emulates that really well. I'm usually using a tight noise gate so I'll have to disable that to make it work that way. But for example the Fryette amp sim works just like the real thing: roll don't the volume and you get a clean tone and roll up the volume and it's full on metal. Axe-Fx has that realistic amp hum but ofcourse some analog factors might be missing... will have to test it out.